The present invention relates to a mass spectrometer and a method of mass spectrometry.
It is known to transfer or guide ions through a region of a mass spectrometer which is maintained at a relatively high pressure. For example, ions may be transported from an atmospheric pressure ion source to a mass analyser which is maintained at a low pressure. It is known to use radio frequency (RF) ion guides comprising a plurality of rods or a plurality of electrodes having apertures through which ions are transmitted in order to transfer or guide the ions. The RF ion guide may be maintained at an intermediate pressure of, for example, 10−3-101 mbar.
An ion trap comprising a plurality of rod electrodes and additional electrodes to confine ions axially within the ion trap is also known. An ion trap comprising a plurality of electrodes having apertures through which ions are transmitted in use is also known.